Guidewire devices having shapeable polymer tips

ABSTRACT

The present disclosure relates to guidewire devices having shapeable tips and effective torquability. A guidewire device includes a core having a proximal section and a tapered distal section. A tube structure is coupled to the core such that the tapered distal section of the core extends into and distally beyond the tube structure. The portion of the core extending distally beyond the tube forms a shapeable tip. A polymer covering encompasses the tip. The tip is configured to reduce the tendency of resilient forces from the tube structure to disrupt a customized shape of the tip.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/611,344, filed Jun. 1, 2017 and titled “GUIDEWIRE DEVICES HAVING SHAPEABLE POLYMER TIPS”, which claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 62/363,760, filed Jul. 18, 2016 and titled “GUIDEWIRE DEVICES HAVING SHAPEABLE TIPS”. The disclosures of each of the foregoing are incorporated herein by this reference.

BACKGROUND

Guidewire devices are often used to lead or guide catheters or other interventional devices to a targeted anatomical location within a patient's body. Typically, guidewires are passed into and through a patient's vasculature in order to reach the target location, which may be at or near the patient's heart or neurovascular tissue, for example. Radiographic imaging is typically utilized to assist in navigating a guidewire to the targeted location. In many instances, a guidewire is left in place within the body during the interventional procedure where it can be used to guide multiple catheters or other interventional devices to the targeted anatomical location.

Some guidewire devices are constructed with a curved or bent tip to enable an operator to better navigate a patient's vasculature. With such guidewires, an operator can apply a torque to the proximal end of the guidewire or attached proximal handle in order to orient and point the tip in a desired direction. The operator may then direct the guidewire further within the patient's vasculature in the desired direction.

Tuning the flexibility of a guidewire device, particularly the distal sections of the guidewire device, is also a concern. In many circumstances, relatively high levels of flexibility are desirable in order to provide sufficient bendability of the guidewire to enable the guidewire to be angled through the tortuous bends and curves of a vasculature passageway to arrive at the targeted area. For example, directing a guidewire to portions of the neurovasculature requires passage of the guidewire through curved passages such as the carotid siphon and other tortuous paths.

Another concern related to guidewire devices is the ability of a given guidewire device to transmit torque from the proximal end to the distal end (i.e., the “torquability” of the guidewire device). As more of a guidewire is passed into and through a vasculature passageway, the amount of frictional surface contact between the guidewire and the vasculature increases, hindering easy movement of the guidewire through the vasculature passage. A guidewire with good torquability enables torqueing forces at the proximal end to be transmitted through the guidewire to the distal end so that the guidewire can rotate and overcome the frictional forces.

Some guidewire devices include a distally placed micro-machined hypotube positioned over the distal end of the guidewire core in order to direct applied torsional forces further distally toward the end of the device. Because torsional forces are primarily transmitted through the outer sections of a cross-section of a member, the tube is configured to provide a path for increased transmission of torque as compared to the amount of torque transmitted by a guidewire core not sheathed by a tube.

While such guidewire devices have provided many benefits, several limitations remain. For example, many of the design characteristics of a guidewire having a torque-transmitting tube, although functioning to provide increased torque transmission, work against and limit the shapeability of the guidewire tip.

BRIEF SUMMARY

The present disclosure relates to guidewire devices having shapeable tips and effective torquability. In one embodiment, a guidewire device includes a core with a proximal section and a distal section. The distal section may taper to a smaller diameter than at the proximal section. A tube structure is coupled to the core such that the distal section of the core passes into the tube structure and passes distally beyond the tube structure to form a shapeable tip. The guidewire device also includes a coil that encompasses at least a portion of the distal portion of the core. The coil is positioned such that a proximal portion of the coil is disposed between an outer surface of the core and an inner surface of the tube structure, and such that a distal portion of the coil extends distally beyond the tube structure to encompass at least a portion of the shapeable tip. The guidewire device also includes a polymer covering encompassing at least part of the distal portion of the coil. The tip is configured to reduce the tendency of resilient forces from the tube structure to disrupt a customized shape of the tip.

In some embodiments, the guidewire device further includes a braided material coupled to a distal end of the tube structure and extending distally from the tube structure. In some embodiments, the braided material is embedded within the polymer covering.

In one embodiment, the core is formed from and/or includes stainless steel, the tube structure is formed from and/or includes a superelastic material such as nitinol, and the coil is formed from and/or includes a radiopaque material such as platinum.

In some embodiments, the tube structure includes a plurality of fenestrations that define a plurality of axially extending beams coupling a plurality of circumferentially extending rings. The tube structure may include one or more of a one-beam, two-beam, three-beam cut pattern, or cut pattern of more than three beams. In some embodiments, a rotational offset is applied between successive segments to minimize preferred bending directions along a length of the tube structure.

Additional features and advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the embodiments disclosed herein. The objects and advantages of the embodiments disclosed herein will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing brief summary and the following detailed description are exemplary and explanatory only and are not restrictive of the embodiments disclosed herein or as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIGS. 1A and 1B illustrate an exemplary embodiment of a guidewire device providing effective torquability and having a polymer encompassed shapeable tip;

FIG. 2 illustrates another embodiment of a guidewire device having a shapeable tip with a braided material embedded within a polymer covering;

FIGS. 3 through 8 illustrate various exemplary cut patterns that may be formed in the tube of the guidewire device; and

FIGS. 9 through 11 illustrate various distal tip configurations that may be utilized with the guidewire device.

DETAILED DESCRIPTION Introduction

The present disclosure relates to guidewire devices providing effective anatomical navigation capabilities. The ability to steer and direct a guidewire to a targeted anatomical location depends on balancing and optimizing tradeoffs between torquability and the ability to maintain a shaped tip. A guidewire device may include a shapeable tip to allow an operator to point the tip in a desired direction within the vasculature by rotating the distal tip. However, if the torquability of such a guidewire device is insufficient, the operator will be unable to transmit torsional forces all the way to the shaped distal tip to control the orientation of the shaped distal tip. This hindrance will become increasingly problematic as the guidewire device is advanced farther into the vasculature and experiences increasing frictional resistance. In addition, if a guidewire device is unable to properly form and maintain a shaped tip, it will have limited ability to adjust tip orientation, making intravascular navigation more difficult.

Embodiments described herein provide one or more features that balance and/or optimize the relationship between guidewire torquability and the ability to form and maintain a shaped tip. Such guidewires are responsive to operator manipulation during guidewire deployment, and provide effective navigation capabilities by enabling a shaped distal tip to receive transmitted torsional forces.

In some embodiments, the shapeable tip allows an operator to custom shape the tip, such as by manually shaping the tip just prior to deploying the guidewire device within the patient's vasculature. The operator is thus enabled to customize the shaping of the distal tip according to preferences and/or conditions particular to a given application. The guidewire device is also configured to effectively transmit torque while maintaining the shaped tip. At least some embodiments described herein include tips that are able to maintain a bent or curved shape throughout a procedure, or throughout multiple procedures, or even indefinitely until subjected to a counteracting reshaping force.

Guidewire Devices with Shapeable Tips

FIGS. 1A and 1B illustrate an exemplary guidewire device 100 having an effective shapeable tip. FIG. 1A illustrates a side view of the device and FIG. 1B illustrates a cross-sectional view of the device. The guidewire device 100 includes a core 102. A tube 104 is coupled to the core 102 and extends distally from a point of attachment to the core 102. As shown, a distal section of the core 102 extends into the tube 104 and is surrounded by the tube 104. In some embodiments, the core 102 includes one or more tapering sections so that the core 102 is able to fit within and extend into the tube 104. For example, the distal section of the core 102 may be ground so as to progressively taper to a smaller diameter at the distal end. In this example, the core 102 and the tube 104 have substantially similar outer diameters at the attachment point 103 where they adjoin and attach to one another.

The tube 104 is coupled to the core 102 (e.g., using adhesive, soldering, and/or welding) in a manner that allows torsional forces to be transmitted from the core 102 to the tube 104 and thereby to be further transmitted distally by the tube 104. A medical grade adhesive/polymer may be used to couple the tube 104 to the core wire 102 at one or more points (e.g., including attachment point 103).

As explained in more detail below, the tube 104 is micro-fabricated to include a plurality of cuts. The cuts are arranged to form a cut pattern which beneficially provides for effective shapeability near the distal tip of the guidewire device 100 while also maintaining good torquability. For clarity, cut patterns are not shown in FIGS. 1A through 2B but will be described with respect to FIGS. 3 through 8.

In some embodiments, the proximal section 110 of the guidewire device 100 extends proximally to a length necessary to provide sufficient guidewire length for delivery to a targeted anatomical area. The proximal section 110 typically has a length ranging from about 50 to 300 cm (about 19.69 to 118.11 inches). The proximal section 110 may have a diameter of about 0.36 mm (about 0.014 inches), or a diameter within a range of about 0.20 to 3.175 mm (about 0.008 to 0.125 inches). The distal section 112 of the core 102 may taper to a diameter of about 0.051 mm (about 0.002 inches), or a diameter within a range of about 0.025 to 1.27 mm (about 0.001 to 0.050 inches). In some embodiments, the tube 104 has a length within a range of about 3 to 100 cm (about 1.18 to 39.37 inches). The tube 104 may be formed from and/or include a superelastic material such as nitinol. Alternatively, the tube 104 may be formed from and/or include a linear elastic material (e.g., with a recoverable strain of at least about 6%). The portion of the device extending distally beyond the tube 104 (referred to as the tip 106) may measure about 0.5 to 5 cm in length, or about 1 to 3 cm in length.

In some embodiments, the distal section 112 of the core 102 tapers to a round cross-section. In other embodiments, the distal section 112 of the core 102 has a flat or rectangular cross-section. The distal section 112 may also have another cross-sectional shape, such as another polygon shape, an ovoid shape, an erratic shape, or combination of different cross-sectional shapes at different areas along its length.

Typically, a user will shape the distal end of the guidewire device 100 by manually bending, twisting, or otherwise manipulating the distal 1 cm to 3 cm (approximately) of the guidewire device 100 to a desired shape. The illustrated guidewire device 100 includes a distal tip 106 which extends distally beyond the tube 104. The tip 106 is configured to be shapeable so that an operator may manually bend, twist, or otherwise manipulate the tip 106 to a desired shape. In some embodiments, the tip 106 includes one or more shapeable components formed from stainless steel, platinum, and/or other shapeable materials. In preferred embodiments, the tip 106 includes one or more components formed from a material that exhibits work hardening properties, such that the tip, when shaped (i.e., plastically deformed), provides a higher elastic modulus at the shaped sections than prior to being shaped.

A coil 114 is positioned partially within the tube 104 upon at least a portion of the distal section 112 of the core 102. The coil 114 extends distally beyond the tube 104 to form part of the tip 106. The coil 114 is preferably formed from one or more radiopaque materials, such as platinum group, gold, silver, palladium, iridium, osmium, tantalum, tungsten, bismuth, dysprosium, gadolinium, and the like. Additionally, or alternatively, the coil 114 may be at least partially formed from a stainless steel or other material capable of effectively holding shape after being bent or otherwise manipulated by a user.

In the illustrated embodiment, the coil 114 is disposed at or near the distal end of the device and extends a distance proximally toward the attachment point 103. In the illustrated device, the majority of the length of the coil 114 extends distally beyond the tube 104. In other embodiments, the coil 114 may extend farther proximally. The coil 114 may extend from the distal end by 1, 2, 4, 6, 8, 10, 12, 15, 20, 25, 30, or 35 cm, or may extend a distance within a range defined by any two of the foregoing values.

In some embodiments, the section of the coil 114 extending distally beyond the tube 104 may be formed from a different material than more proximal sections of the coil 114. For example, the distal section of the coil 114 may be formed from stainless steel and/or other materials primarily selected to provide effective shapeability, while the proximal sections of the coil 114 are formed from platinum or other materials primarily selected to provide effective radiopacity. In some embodiments, the coil 114 is formed as one integral piece. In other embodiments, the coil 114 includes a plurality of separate sections stacked, positioned adjacent to one another, and/or interlocked through intertwining coils. Such separate segments may additionally or alternatively be soldered, adhered, or otherwise fastened to one another to form the complete coil 114.

Although the illustrated embodiment shows a space between the outer surface of the coil 114 and the inner surface of the tube 104, it will be understood that this is done schematically for ease of visualization. In some embodiments, the coil 114 is sized to fill and pack a greater proportion of the space between the core 102 and the tube 104. For example, the coil 114 may be sized so as to abut both the outer surface of the core 102 and the inner surface of the tube 104. Some embodiments may include a space between the core 102 and the tube 104 for at least a portion of the section of the guidewire device 100 where the tube 104 and the core 102 are co-extensive.

The portion of the coil 114 disposed within the tube 104 may beneficially function to pack the space between the core 102 and the tube 104 so as to align the curvature of the distal section 112 of the core 102 with the curvature of the tube 104. For example, when a curvature is formed in the tube 104, the closely packed segments of the coil 114 function as a packing between the tube 104 and the distal section 112 to impart the same curvature to the distal section 112. In contrast, a core of a guidewire device omitting such packing, may not follow the same curve as the tube but may extend until abutting against the inner surface of the tube before being forced to curve.

As shown, the tip 106 extends further distally than the tube 104. The illustrated configuration beneficially allows the tip 106 to be shaped to a desired position relative to the tube 104 and the rest of the guidewire 100 and to remain in the shaped position for a sufficiently extended period of time. In contrast to a guidewire device relying on shapeability of a tube or upon shapeable components disposed more fully within a tube, the illustrated tip 106 is able to maintain a shaped configuration without being subjected to counteracting forces imparted by the tube 104 itself.

In addition, as described more fully below, the tube 104 may include a cut pattern which maintains effective torquability while also providing sufficient flexibility at the distal region of the tube 104 so as to avoid disrupting the custom shape of the tip 106. In preferred embodiments, the shapeable distal section of the core has a stiffness that is able to withstand an expected bending force from the tube acting upon the distal section of the core after it has been shaped. In some embodiments, the shapeable distal section of the core is formed from a material or combination of materials providing a modulus of elasticity that is about 1.5 to 4 times greater, or about 2 to 3 times greater than the modulus of elasticity of the material(s) used to form the tube.

In contrast to the illustrated embodiments, a guidewire device which relies on shaping of a tube to provide a desired distal tip shape will not be capable of holding the shaped configuration or will only be capable of holding the shaped configuration for a relatively short period of time. This degradative effect on the shaped tip happens at least in part because tube structures are typically formed from nitinol or other superelastic materials. Such tubes will be biased, upon being bent or shaped, toward their original (e.g., straight) position, and will impart recovery forces against any shapeable internal components, resulting in deformation and a loss of the customized shape of the tip.

Often, for example, a guidewire that distally terminates with a tube structure or that otherwise substantially relies on bending of the tube structure to shape the tip will have a shaped tip prior to deployment. However, the shaped tip will be lost or degraded during use of the guidewire as the superelastic tube flexes toward its original shape in opposition to the desired tip shape. In contrast, embodiments described herein provide tips capable of being shaped without being subjected to deforming recovery forces of adjoining components of the guidewire device.

The illustrated guidewire device 100 also includes an outer polymer covering 118 formed of a medical grade polymer material. The polymer covering 118 bonds to and encompasses the distally extending sections of the coil 114 and the core 102. The polymer covering 118 beneficially provides an atraumatic covering with high relative flexibility. The high relative flexibility allows the tip 106 to be custom shaped without being subjected to counteractive elastic or superelastic recovery forces. As shown, the polymer material forming the polymer covering 118 may also extend over the distal tip of the core 102 to form an atraumatic terminus 120.

In some embodiments, the polymer covering 118 is doped with a radiopaque substance, such as barium, bismuth, tungsten, and the like. For example, in embodiments, where the coil 114 is formed from a relatively less radiopaque material (e.g., stainless steel), the polymer covering 118 may be configured to provide sufficient radiopacity to the tip 106.

In some embodiments, the polymer used to form the polymer covering 118 is bonded to one or more interior portions of the tube 104. For example, an amount of the polymer material may be positioned within the tube 104 to assist with packing of spaces between the core 102 and the tube 104. In some embodiments, the polymer may be utilized as a substitute for some or all of the pack provided by the coil 114, such that the coil may be omitted or adjusted with respect to outer diameter, coil wire size, coil spacing, and/or length, for example.

The medical grade polymer material may be formed from and/or include one or more medical grade adhesives. In some embodiments, for example, the polymer material may be an acrylate-based adhesive curable through ultraviolet and/or visible light application. The polymer material may also include one or more elastomeric fillers, adhesion promoters, leveling agents, and/or curing accelerators.

FIG. 2 illustrates an alternative embodiment of a guidewire device 200 having a polymer covered braided section 218 forming part of the shapeable tip 206. The guidewire device 200 may otherwise be configured in a manner similar to the guidewire device 100 of FIG. 1, and like reference numbers refer to like features/components. The guidewire device 200 therefore includes a core 202 having a proximal section 210 and a distal section 212. The distal section 212 extends into and distally beyond the tube 204 to form a shapeable tip 206. The tube 204 may be attached to the core 202 at the attachment point 203. A coil 214 formed from a radiopaque and/or shapeable material encompasses at least a portion of the core 202 that extends distally beyond the tube 204, and may extend proximally to partially reside within the tube 204.

In this embodiment, the distal tip 206 includes a polymer covered braid 218. The braid 218 surrounds at least the distally extending portion of the coil 214 and may function as an embedding structure for the polymer material. The braid 218 advantageously provides for the transmission of some torque from the tube 204 to the distal tip 206 while still providing effective flexibility allowing the tip 206 to be maintained in a shaped configuration. The braid 218 may be formed from and/or may include a suitable metal mesh material, such as a stainless steel mesh. The polymer material in which the braid 218 is embedded may include a radiopaque filler such as barium sulfate and/or any other radiopaque material described herein.

Cut Patterns

FIGS. 3 through 8 illustrate exemplary embodiments of tube cut patterns that may be utilized in one or more of the guidewire device embodiments described herein. For example, the tube 104 of the embodiment shown in FIGS. 1 and 2 may be cut according to one or more of the configurations shown in FIGS. 3 through 8.

Cut patterns are referred to herein according to the number of axially extending beams disposed between each pair of adjacent circumferentially extending rings. FIGS. 3 and 4 illustrate “one-beam” cut patterns, FIGS. 5 and 6 illustrate “two-beam” cut patterns, and FIG. 7 illustrates a “three-beam” cut pattern. Other embodiments may include more than three beams between each pair of adjacent rings (e.g., a four-beam cut pattern, five-beam cut pattern, etc.).

The tube structure 304 illustrated in FIG. 3 includes a single beam 332 disposed between each pair of adjacent rings 334. Pairs of adjacent beams may alternate by 180 degrees, as shown. Additionally, or alternatively, sections may include beams positioned on a single side along a length of the tube, as shown by the beams 432 and rings 434 of the tube 404 of FIG. 4.

The tube structure 504 illustrated in FIG. 5 includes a pair of circumferentially opposing beams 532 disposed between each pair of adjacent rings 534. The corresponding beams 532 in each pair may be symmetrically circumferentially spaced (i.e., by about 180 degrees) as shown by FIG. 5. Alternatively, the corresponding beams may be circumferentially non-symmetric, as shown by the beams 632 and rings 634 of the tube 604 of FIG. 6. The tube structure 704 illustrated in FIG. 7 includes a triad of beams 732 disposed between each pair of adjacent rings 734. The corresponding beams in each triad may be symmetrically circumferentially spaced (i.e., by about 120 degrees) as shown, or may be positioned according to some non-symmetric arrangement.

Generally, the higher the number of beams left between each pair of adjacent rings, the relatively greater the stiffness of the tube. Cut patterns may therefore be selected to provide a desired flexibility profile along the length of the tube. Cut spacing, width, and/or depth may also be varied to provide desired flexibility characteristics. For example, one tube configuration can include a proximal section with relatively lower flexibility and relatively higher torquability that rapidly progresses to a distal section with relatively higher flexibility and relatively lower torquability. Beneficially, the flexibility provided by such cut patterns can minimize or prevent the tube from deforming the shape of the internal structures of the guidewire (e.g., the core) so that a customized shape of the tip can be better formed and maintained.

A section of tube having a two-beam cut pattern with substantially circumferentially equally spaced beams (as in FIG. 5) will typically have relatively higher ability to transmit torque and relatively lower flexibility, while a section of tube having non-symmetrically spaced beams (as in FIG. 6) will typically have a torque transmissibility and flexibility between that of a symmetrically spaced beam pattern and a one-beam pattern (as in FIG. 3). The less circumferentially symmetric the corresponding pair of beams are positioned, the closer together circumferentially the resulting beams will be, and therefore the more similar the non-symmetric two-beam cut will be to a one-beam cut pattern. Such a non-symmetric two-beam pattern may therefore be used as a transition between a symmetric two-beam pattern and a one-beam pattern.

The cut patterns may form “segments” of repeating structural units along a length of the tube. In a typical one-beam embodiment, a single segment can be defined as a first beam 332 disposed between two adjacent rings 334 (one proximal ring and one distal ring) and a second opposing beam 332 extending from the distal ring and being rotationally offset by about 180 degrees from the first beam 332. Likewise, in a typical two-beam embodiment, a single segment can be defined as a first pair of beams 532 disposed between two adjacent rings 534 (one proximal ring and one distal ring) and a second pair of beams 532 extending from the distal ring and being rotationally offset from the first pair of beams by about 90 degrees. Likewise, in a typical three-beam embodiment, a single segment can be defined as a first triad of beams 732 disposed between two adjacent rings 734 (one proximal ring and one distal ring) and a second triad of beams 732 extending from the distal ring and being rotationally offset from the first triad by about 60 degrees.

FIG. 8 illustrates a tube 804 having a plurality of beams 832 and rings 834. The illustrated cut pattern includes a rotational offset applied at each successive segment of the tube 804 to minimize preferred bending directions in the tube. As used herein, a “rotational offset” is the angular rotation between two adjacent segments. A rotational offset is therefore applied from one segment to the next, even though individual cuts within a segment may also be offset from one another.

As shown, the cuts may be arranged to form a substantially consistent rotational offset from one segment to the next. The illustrated cut pattern shows a rotational offset of about 5 degrees from one segment to the next. When multiple successive segments having such an angular offset are formed, the resulting pattern of beams along a sufficient length of the tube 804 wraps around the axis of the tube 804 in a continuously rotating helical pattern. The angular offset may be about 5, 15, 30, 45, 60, 75, 80, or 85 degrees. In some embodiments, the angular offset is applied at each successive segment. In other embodiments, a plurality of successive segments are disposed next to one another without an offset before the angular offset is applied.

The illustrated example shows a two-beam cut pattern with a series of rotational offsets. It will be understood, however, that the same principles may be applied to other cut patterns, such as a one-beam cut pattern, three-beam cut pattern, or cut pattern having greater than three beams per pair of adjacent rings. In preferred embodiments, each successive cut or sets of cuts (e.g., every second cut, third, fourth, etc.) along the length of a given section is rotationally offset by about 1, 2, 3, 5, or 10 degrees, or is offset by about 1, 2, 3, 5, or 10 degrees off from 180 degrees in a one-beam pattern, 1, 2, 3, 5, or 10 degrees off from 90 degrees in a two-beam pattern, 1, 2, 3, 5, or 10 degrees off from 60 degrees in a three-beam pattern, and so on for patterns having a higher beam count. These rotational offset values have beneficially shown good ability to eliminate flexing bias.

The separate components and features of the cut patterns shown in FIGS. 3 through 8 may be combined to form different tube configurations. For example, some tubes may be configured so as to have a section of two-beam cuts which transitions to a section of one-beam cuts.

Tip Variations

FIGS. 9 through 11 illustrate embodiments of various distal tip configurations that may be utilized with one or more of the embodiments described herein. FIG. 9 illustrates a continuous diameter tip configuration. Where the coil 918 surrounding the tapering core 902 has a substantially continuous diameter. FIG. 10 illustrates a stepped tip configuration where an outer coil 1018 positioned over the core 1002 has a substantially continuous diameter. A smaller diameter inner coil 1014 is positioned so as to extend further distally than the outer coil 1018 to provide a step-wise change in diameter of the tip. FIG. 11 illustrates a tapered tip configuration where the coil 1118 is tapered so as to match a taper of at least a portion of the core 1102. The tip embodiments illustrated in FIGS. 9 through 11 may be combined with any of the guidewire device embodiments described herein. For example, a desired tip configuration may be selected so as to provide desired shapeability and/or flexibility characteristics for a given guidewire application.

The terms “approximately,” “about,” and “substantially” as used herein represent an amount or condition close to the stated amount or condition that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” and “substantially” may refer to an amount or condition that deviates by less than 10%, or by less than 5%, or by less than 1%, or by less than 0.1%, or by less than 0.01% from a stated amount or condition.

Elements described in relation to any embodiment depicted and/or described herein may be combinable with elements described in relation to any other embodiment depicted and/or described herein. For example, any element described in relation to a tube section of any of FIGS. 3 through 8 and/or any element described in relation to a tip configuration of any of FIGS. 9 through 11 may be combined and used with the guidewire devices of FIGS. 1A, 1B, and 2. In any of the foregoing combinations, the distal tip of the core wire may be rounded, flat, or another shape.

The present invention may be embodied in other forms, without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

What is claimed is:
 1. A guidewire device comprising: a core having a proximal section and a distal section, the distal section having a smaller diameter than the proximal section; a tube structure coupled to the core such that the distal section of the core passes into the tube structure and passes distally beyond the tube structure to form a tip; a braided material coupled to a distal end of the tube structure and extending distally from the tube structure, the braided material encompassing at least a portion of the tip; and a polymer encompassing at least a portion of the tip.
 2. The guidewire device of claim 1, wherein the distal section of the core tapers from the proximal section of the core.
 3. The guidewire device of claim 1, wherein the tip extends distally beyond the tube a distance of about 0.5 cm to 5 cm.
 4. The guidewire device of claim 1, further comprising a coil partially disposed within the tube structure and partially extending distally beyond the tube structure.
 5. The guidewire device of claim 4, wherein the portion of the coil extending distally beyond the tube structure is encompassed by the polymer.
 6. The guidewire device of claim 4, wherein the portion of the coil disposed within the tube structure encompasses the core and is positioned between an outer surface of the core and an inner surface of the tube structure.
 7. The guidewire device of claim 4, wherein the coil is formed from a material more radiopaque than stainless steel.
 8. The guidewire device of claim 4, wherein the coil includes a portion disposed within the tube structure and a portion that extends distally beyond the tube structure, wherein the portion that extends distally beyond the tube structure is longer than the portion disposed within the tube structure.
 9. The guidewire device of claim 1, wherein the tube structure is formed from nitinol.
 10. The guidewire device of claim 1, wherein the core is formed from stainless steel.
 11. The guidewire device of claim 1, wherein the polymer covering includes a radiopaque material.
 12. The guidewire device of claim 1, wherein the polymer is integrated with the braided material.
 13. The guidewire device of claim 1, wherein the tube structure includes a plurality of fenestrations defining a plurality of axially extending beams coupling a plurality of circumferentially extending rings.
 14. The guidewire device of claim 12, wherein the plurality of fenestrations are arranged into one or more of a one-beam cut pattern, two-beam cut pattern, or three beam-cut pattern.
 15. The guidewire device of claim 12, wherein the fenestrations define a cut pattern having a rotational offset such that each successive segment along a length of the tube structure is circumferentially rotated from a previous segment.
 16. The guidewire device of claim 12, wherein the fenestrations define a cut pattern with cuts of increasing depth toward a distal end of the tube structure and/or with spacing between successive cuts that decreases toward a distal end of the tube structure.
 17. A guidewire device comprising: a core having a proximal section and a distal section, the distal section having a smaller diameter than the proximal section; a tube structure coupled to the core such that the distal section of the core passes into the tube structure and passes distally beyond the tube structure to form a tip; a coil encompassing at least a portion of the distal section of the core, a portion of the coil being disposed within the tube structure, and a portion of the coil extending distally beyond the tube structure to encompass at least a portion of the tip, wherein the portion of the coil extending distally beyond the tube structure is longer than the portion disposed within the tube structure; and a polymer covering coupled to a distal end of the tube structure and extending distally from the tube structure, the polymer covering encompassing the portion of the inner coil extending distally beyond the tube structure.
 18. The guidewire device of claim 17, further comprising a braided material attached to the distal end of the tube structure.
 19. The guidewire device of claim 18, wherein the braided material is embedded within the polymer covering.
 20. A guidewire device comprising: a core having a proximal section and a distal section, the distal section having a smaller diameter than the proximal section; a tube structure coupled to the core such that the distal section of the core passes into the tube structure and passes distally beyond the tube structure; a coil partially disposed within the tube structure and partially extending distally beyond the tube structure; a braided material coupled to a distal end of the tube structure and extending distally from the tube structure, the braided material encompassing at least a portion of the coil; and a polymer integrated with the braided material and encompassing at least a portion of the coil. 